Method of making container caps or closures



Feb. 27, 1940. c. HAMMER METHOD OF MAKING CONTAINER CAPS OR CLOSURESOriginal Filed July 21, 1937 2 Sheets-Sheet 1 11v VENTOR Hwnme P ATTORNEY' Patented Feb. 27,

PATENT omcs ltlETHOD OF MAKING CONTAINER CAPS 03 CLOSURES CharlesHammer, Garden City, N. Y.

' Original application July 21, 1937, Serial No.

154,747, now Patent No.

2,175,350, dated October 10, 1939. Divided and this application June 1,1939, Serial No. 276,820

10 Claims.

This invention relates to caps or closures for containers orreceptacles, it more particularly relating to the method of making animproved preformed, rotatable severable reseal cap where-. I by acontainer or receptacle such as a bottle or jar may be effectivelysealed and rescaled and yet so constructed that, when replaced on thecontainer, the cap will indicate that the container has been opened andthus prevent tampering with the contents thereof, the presentapplication being a division of my U. S. Letters Patent 2,175,350

of October 10, 1939.

An object of the present invention is the-provision of a method ofmaking an improved cap severable without the use of objectionablescoring, score lines or tear-oft strips.

In the manufacture of severable caps, it has been the practice toaccomplish this result either icy scoring the can so as to enable onepart of the cap to be severed from another part thereof along the scorelines or by providing tear-off strips.

The art has recognized that score linesare objectionable because of thedifficulty of accurately gau ing the depth oi? the score lines since, ifnot scored deeply enough, the cap will not tear, or will tear unequally.Consequently, the accuracy required has made the caps diiiicult tomanufacture and, therefore, unsatisfactory to manufacturers especiallyin view of the factthat repeated use of scoring tools afiects theire'fiiciency and causes complaint by customers.

Tear-ofl strips are also objectionable since, frequently, it isdiflicult to sever the strip along a predetermined line, resulting in'but a portion 35 of the band being removed and requiring theapplication of tools to remove the cap. Also, it is not infrequent thatmanipulation of such strips results in injuries to the hands of the userwhich have sometimes proven serious. Consequently, customers have takena strong dislike to such type of caps. Therefore, it is the object ofthe present improvement to provide a severable cap which is notdependent upon either score lines or tear-oi! strips or the application01' tools to insure removal.

Metal caps or closures which indicate tampering with the contentsof acontainer have been patented but they have either not proven verysuccessful or are of that form in which the cap is made of some thinpliable metal which will permit the cap to be pressed or molded on tothe container to conform to the shape thereofin-other words, caps ofpliable metal in which the locking, elements such as are formed when the65. cap is applied to the container, and, therefore,

.on a machine and applied to the container without the necessity ofshaping or molding it thereon, which requires time and is expensive,while its re-use to preserve the contents of the container, due to itslight and flimsy character, is 10 materially interfered with.

' Another object of the invention therefore, as hereinbefore stated, isto provide an improved preformed cap, that is, one in which the cap maybe efficiently and inexpensively made by ma- 15 chinery and shipped inquantities for quick and easy application to containers without themolding or shaping of the threads while on the container.

Furthermore, it has been the practice to use, in connection'withrotatable caps, sealing disks for. sealing the edge of the container butI believe I am the first to provide a combined severable cap and sealingmedium which will not only indicate that the contents of the containerhave 25 been tampered with but will efdciently seal the upper edge ofthe container and also the interior neck thereof.

Therefore, one of the objects of the present improvement is theprovisionof an improved cap 30 readily severable without the use of objectionabletear-oil strips or score lines to indicate tampering with the contentsof the container and having combined therewith a sealing medium of suchform that it will eiiiciently seal not only the upper edge of thecontainer but also the interior neck.

In the drawings accompanying and forming a part of this specification,

Fig. 1 illustrates in section this improved cap applied to the neck of acontainer such as a bottle. I

Fig. 2 illustratesthis improved cap in section partly rotated in adirection opposite to that required for its application.

Fig. 3 illustrates this improved cap in section and having the improvedsealing medium attached thereto.

Fig. 4- illustrates the upper portion of a container with the capsevered and the rescaling part thereof removed.

Fig. 5 is a sectional view illustrating a step in the method of makingthis improved cap- Fig. 6 illustrates a sectional view of another stepin the method of making this improved cap. I

- Fig. 7 illustrates in section, the weakening of a portion of the smrtof a cap prior to the formation of the severable projection.

Fig. 8 is an enlarged view of a portion oi the cap illustrating thecompressed, weakened, severable flange, and Y Fig. 9 illustrates themanner in which the weakened flange is stretched during the rotation ofthe cap oil. of the container to sever it along the apex of the flangeshown in Fig. 8.

Similar characters of reference indicate corre- I spondingparts in theseveral views.

Before explaining in detail the present improvement and mode ofoperation thereof, I desire to have it understood that the invention isnot limited to the details of construction and arrangement of partsillustrated in the accompanying drawings since the invention is capableof other embodiments, and that the phraseology employed is for thepurpose of description and not of limitation.

In the preferred form of cap herein shown, it is illustrated as athreaded cap although, obviously, it could be made with any suitablerotatable locking elements if desired and the improvements may be usedwith various styles of caps.

In the'present instance, the cap comprises a top 2 and a depending smrt3 having locking ele-' weakened annular severable flange and, consementssuch as threads a formed on the smrt.

Below these locking elements, the cap is pmvlded with an annularweakened exteriorly projecting compressed flange 5 having therebelow adepending portion 6 which may be readily bent or spun around a. shoulderI of the container, thereby permanently securing the lower part of thecap to the bottle, this bending, of course,

taking place after the cap has been completely the cap and projectionsIE on the interior'while the annular severable flange is first formed asa shallow groove M on the interior of the cap and a projection IS on theexterior.

During this rolling operation, that part of the tool forming the annularprojection i5 alsoacts upon the metal forming the projection bothexteriorly and interiorly as at l6 and I1 (see Fig.

5), thereby weakening it although, if preferred,

the weakening of the cap skirt where this projection is to be formed maytake place prior to" the rolling of the threads and the projection intothe skirt, (see Fig. 7) by suitable male and female rolls i8 and I9whereby the metal of the skirt is provided with an annular weakened band20, (see Fig. .7), at which point themetal, due to this weakeningoperation, is shown thinner and, therefore, weaker, as at 2!, than otherportions of the cap.

Subsequent to the formation of the locking threads and the shallowgroove forming the projecting severable flange, the weakened portion ofthe metal of the cap is subjected to compression by suitable male andfemale dies 22 and 23 depthwise of the cap, (see Fig. 6) so that thewalls of the shallow groove are compressed. into substantialjuxtaposition; as illustrated at 24 (see Fig. 6), thereby sharplybending the apex of the quently, further weakening it.

greases Fig. 6 illustrates the cap in position in the dies, the diespaced from the shallow severable flange at the left side while, at theright side, the die has been shifted to compress the weakened walls ofthis severable flange into juxtaposition.

The lower portion 5- of the skirt of the cap and the upper portion 5" ofthe depending portion 8 are weakened whereby they are of less thickness,

as at 28, thus weakening this portion of the cap.

and it is at this thinned area that the cap is provided with theoutwardly extending compressed flange 5.

In practice, if preferred, the weakened portion at or adjacent to theapex of the annular severable flange maybe scored as indicated by thedotted lines in Figs.'1and 3, which also indicate the bend of thematerial, thereby further to weaken it ii founddesirable since, in viewof the fact that the weakened portion of the cap does not dewnd entirelyupon such scored line, the objectionable features of such scoring, ashereinbefore referred to, are not present. I

The cap may be provided with a suitable exteriorly knurled portion bymeans of which the cap maybe rotated OK or on to the container, asdesired.

At the time the projecting weakened severable flange is squeezed orcompressed, the entire cap and one that is more nearly to the pitch linethan has been possible heretofore.

Heretoiore, in forming thread grooves in caps, the larger or deeper thethread in the cap, the smaller the threading tool or-roli must be onwhich it is-iormed since the cap must be readily removable from thethreading tool or roll so that a small thread roll cannot very well makea true pitch in a large cylinder or cap, but by forming the shallowgrooves in the first instance to form .the threads and then reformingthem, a truer and better thread is obtained since the closer the capdiameter. is to the diameter of the tool or roll that makes the thread,the nearer, the pitch of the thread will be obtained.

The cap may be used with suitable liners 26 purpose, the outer edge ofthe flange'is squeezed into an annular recess 29 formed in the cap.

Thus, in practice, the combined cork and cap may be applied or removedin a single operation, the rotation of the cap on to the bottle tightlycompressing the cork thereint'o and. at the same time, the rotation ofthe cap in the opposite direction removing the cork with; the threadedportion of the cap, leaving the lower portion 6 spun around the shoulderof the container (see Fig. 4).

In the' present improvement, the gradual rotation of the. cap ofi'of thecontainer results in opening and spreading the annular severableprojection 5, (see Figs. 2 and 9) thus further weakeningthe alreadyweakened-or partially cracked metal at the apex of, the projection, andas the continued rotation of the cap oi! of the container takes place,this'will readily break and separate the capon a circumferential line atthe apex of v the projection without the necessity of a tearing drawsthe two walls and 5 (see Fig. 9) apart and so lengthens them that thetwo parts will not properly fit together thereafter. When, consequently,the upper part of the cap is turned on to reseal the bottle, as the twoparts no longer fit together, it can be readily detected both by thehand and the eye'that the container has been unsealed and tampered with.

Thus, it will be seen that when the cap is rotated off of the container,that portion of the cap having the locking threads will be broken awayalong the weakened apex of the annular projection 5, leaving the lowerpart of the cap 6 permanently secured tothe'bottle atthe shoulder andwith a raw edge 30 (see Fig. 4) projecting upwardly since this dependingportion Sis unweakened and, consequently, insures the severance of onepart of the cap from another along the apex of the projection so that,while the threaded portion of the cap may be replaced to reseal thebottle to preserve its contents, it is' impracticable effectively toreplace it to conceal this edge. v

Thus, the user will immediately know that the bottle has been previouslyopened or tampered with whereas, with those caps that merely have adepending skirt provided with a slot or scored weakened lower portionand no outwardly extending annular ridge or projection, there is nothingto indicate when the cap has been replaced or that the bottle has beenopened previously because, the adjacent portions of the depending skirtcan be brought so closely together as to appear practically as thoughthe cap had never been removed. In other words, neither the eye nor handcan readily detect the fact that the cap portions have been'previouslyseparated. In the present improvement, however, not only will thestretched and projecting raw edge of the separated portions of the capindicate that the cap has been previously removed or tampered with byinspection, but the raw edge will indicate to the hand of the user suchfact and this cannot well be concealed by any manipulation of the capportions. Therefore, I apprehend that I have provided a severable capwhich not only can be preformed and, hence, made in quantities prior totheir knurling, preferably to form fine grooves or'in-f application tocontainers, but I have provided one which will effectively andefficiently prevent tampering with the contents without detection.

The term weakened as used herein, has reference to that particularmechanical action in which a rolling tool is used to thin the metal inany desired way as by compression, milling or dentations across the faceof the metal and in this operation, the metal can be so thinned or evenperforated and thus so weakened that, in rotating the cap off of thecontainer, the parts thereof will be readily severed without the use oftear-off strips or scoring.

It is to be understoodthat, by des cribing in detail herein anyparticular form, structure or arrangement, it is not intended to limitthe invention beyond the terms of the several, claims or therequirements of the prior art.

Having thus explained the nature of my said invention and described away of constructing and having a skirt with locking elements therein Yfor rotatably securing the cap onto a container which consists inproviding the skirt-with a weak-,

ened-wall shallow groove. on the interior by,

thinning the walls of the groove throughout and then compressing the twowalls only of the groove into juxtaposition to form an annularprojection having a weakened portion.

2. The method of making a preformed closure cap capable of reuse. forthe life of the container and having a skirt with looking elementstherein for rotatably securing the cap on to a container which consistsin providing the skirt with a thinwalled shallow groove by rolling andgrooving the metal of the skirt at such grooved portion to thin thewalls of the groove throughout to form a weakened part and thencompressing the two walls only of the groove into substantialjuxtaposition to form an annular'projection having a weakened portion.

3. The method of making a preformed closure cap capable of reuse forthelife of the container and having a skirt with locking elements thereinfor rotatably securing the cap on to a container which consists inproviding the skirt with a weakened wall shallow groove by rolling andscoring and grooving the metal of the skirt to thin the walls of thegroove throughout and then compressing the two walls only of the grooveinto substantial juxtaposition to form an annular.

cap capable of reuse for the life of the container and having a skirtwith looking elements therein for rotatably securing the cap on to acontainer and with a depending bendable portion adapted to be bentaround the shoulder of a container which consists in decreasing thethickness of the metal at the lower portion of said skirt and the topportion of said depending portion to thin such metal portions throughoutthereby to weaken it and then compressing the metal only of thisweakened portion into substantial juxtaposition to form an annularweakened projection readily severable at the apex thereof.

5. The method of making a preformed closure cap capable of reuse for thelife. of the container and having a skirt with looking elements thereinfor rotatably securing the cap on to a container and with a depending tobe bent'around the shoulder of a container which consists in decreasingthe thickness of the bendable portion adapted metal at the lower portionof said skirt and the top portion of said depending portion to thin suchmetal portions throughout thereby to-weaken it and then compressing themetal only of this weakened portion into substantial juxtaposition toform an annular weakened projection extending beyond the plane of saidskirt and depending portion, and readily severable at the apex thereof.

6. The method of making a preformed closure cap capable of reuse for thelife of the container and having a skirt with locking elements thereinfor rotatably securing the cap on to a container and with a dependingbendable portion'adapted to be bent around the shoulder of a containerwhichconsists in providing the skirt with an interior weakened-wallshallow groove at the juncture of said skirt and depending portion bythinning the walls of the groove throughout,

then compre the two walls only oi the e into substantial juxtapositionto form a weakened annular projection extending beyond the planeof saidskirt and depending portion.

'7. The method of making a preformed closure cap capable of reuse forthe life of the container and having a skirt with looking elementstherein for rotatably securing the cap on to a container and with adepending bendable portion adapted to be vbent around the shoulder of acontainer which consists in providing the skirt with an interiorweakened-wall shallow groove at the juncture of said skirt and dependingportion by roll ing and grooving the metal of the skirt to thin thewalls of the groove throughout and then compressing the two walls onlyof the groove into substantial juxtaposition to form a weakened annularprojection extending beyond the plane of said skirt and dependingportion.

8. The method of making a preformed closure cap capable of reuse for thelife of the container and having a skirt with locmng elements thereinfor rotatably securing the cap on to a container and with a dependingbendable portion adapted to be bent around the shoulder of a containerwhich consists in providing the smrt with an interior weakened-wallshallow groove at thejuncture of said skirt and depending portion byrolling, scoring and grooving the metal of the skirt to thin the wallsof the groove throughout and then compressing the two walls only of thegroove into substantial juxtaposition to form a weakened annularprojection extending endthe plane oi said smrt and depending w ,rer,e

9. The met oi mamng a-preformed closure cap cable of reuse for the lifeof the container and having a smrt which consists in providing the withrelatively shallow lochng threads for rotatably securing the cap on to acontainer and also providing the skirt with an interior thin-walledshallow groove by grooving and decreasing the thickness of the walls ofsaid groove, then compr the two walls only of the groove into jpositionto form an annular projection having a weakened portion andsimultaneously subjecting the cap to endwise compression thereby toreform the shallow thread grooves to give them greater depth ofprojection.

10. The method of mamng a preformed closure cap capable of reuse for thelife of the container and having a skirt with locking elements thereinfor rotatably securing the cap on to a container and with a depending.bendable portion adapted to be bent around the. shoulder of a container,which consists in forming an annular recess at the top of the skirt forthe reception of the flange of a cork and providing the skirt with aninterior weakened-wall shallow groove at the juncture of said skirt anddepending portion by thinning the walls of the groove throughout andthen compressing the two walls only of the groove into substantialjuxtaposition to form an annular weakened projection extending beyondthe plane of theskirt and depending portion.

